Multiple meningiomas: clinical, radiological, surgical, and pathological findings with outcome in four cats

Abstract

The present report describes the clinical signs, magnetic resonance imaging (MRI) findings, surgical procedure, pathological findings and follow-up in four cats with multiple meningiomas; three castrated male and one spayed female domestic shorthair indoor cats, ranging in age from 11 to 14 years. In three of four cats, clinical signs at presentation were suggestive of a focal lesion. Three cats had two meningiomas and one had four meningiomas. Most of the tumours were supratentorial, one arose from the tentorium and one was infratentorial. The duration of presenting signs before surgery ranged from 10 days to 11 months. Postoperative MRI revealed complete gross tumour removal in three cases. In one cat with two cranial fossa meningiomas, subtotal excision with a small basal remnant (2 x 2 mm) of the ventral part of one meningioma lying on the floor of the skull, was observed. Based on histopathological architecture, six tumours revealed features of a transitional subtype meningioma, and four of a meningotheliomatous meningioma. In each cat, the multiple meningiomas were all assigned to the same histopathological group. The preoperative presenting signs had resolved by the follow-up examinations 4 weeks after surgery in two cats. Long-term follow-up evaluation revealed that surgically-induced or exacerbated neurological deficits in two cats had completely or almost completely resolved within 8 weeks of surgery. All patients are still alive 12 to 21 months after surgery and no clinical signs of recurrence could be detected at that time.

Fig 1

A: Case 2, contrast enhanced FE 3D MPR, T1-weighted, dorsal plane, before surgery. Three enhancing meningiomas (arrows) can be seen on the patient's left side. The lateral ventricles (V) are displaced to the right side. (F: frontal sinus). The fourth tumour lying more ventrally on the right side is not visible. B: Case 2, postoperatively. Hypointense (air) spaces can be seen instead of the meningiomas. There is enhancement of the meninges in the region of the most rostral tumour (arrow), either due to reactive inflammation or focal infiltration.